Self-locking valve bag



Aug. 18, 1931. M. R. KENDALL SELF LOCKING VALVE BAG 4 Sheets-Sheet Filed Feb.

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gwuento'c MarvinRKenda/l.

M, M W a g- 18, 93 M. R. KENDALL 1,819,421

SELF LOCKING VALVE BAG Filed Feb. 3, 1930 4 Sheets-Sheet 2 gwuantoz MarvinRKenda/L 1931- M. R. KENDALL 1,819,421

SELF LOCKING VALVE BAG 7 Filed Feb. 3, 1930 4 Sheets-Sheet 3 I I I I I I I I I I I I I I 3 M. R. KENDALL 1,819,421

SELF LOCKING VALVE BAG Filed Feb. 5, 1930 4 Sheets-Sheet 4 fi/qririn R. Kendall.

Patented Aug. 18, 1931 UNITED STATES MARVIN B. OI 293T. TOWNSEND, WASHINGTON snLr-Locxnao vanvn BAG- Application flled I ebruary8,1930.- Serial No. 425,457.

This invention relates to valve bags, and more particularly to a valve constructed to interfold along predetermined fold lines and securel block the inlet opening against es- 5 cape o the contents of the bag therethrough. It is customary, in constructing valve bags, to form inwardly projecting flaps beside the inlet opening and to rely upon the outward pressure of the material in the filled bag to 10 crumple these flaps into the opening so as to block escape of the material. Sometimes the flaps crumple in such a way as to leave passages'through their folds, and'materlal slfts out through these passages.

By this invention there is effected the folding of the flaps along predetermined fold lines, and preferably so as to overlap and completely close the in ct opening against leakage. Preferably, means is provided tending 2 to hold the flaps in their closed, overlapped position, after they have once been moved thereto.

The invention is directed especially to valves in paper bags closed by sewed seams,

25 and to such bags wherein the valve openings are spread in the plane of the bag and collapsed transversely thereto while the empty bags are being shipped or stored prior to ing, but are spread transversely of the plane of the bag after the bag is filled.

Details of the invention will appear as the description proceeds. In the accompanying drawings, forming a part of this specification, one embodiment of the invention is illustures are indicated.

Figure 1 is a view of a sheet which is formed into a sleeve for a valve; Figs. 2 and 3 are views of triangular blanks which are attached to the sheet shown in Fig. 1; Fig. 4 is an isometric view of the sheet shown in Fig. 1, with the blanks of Figs. 2 and 3 attached and with the sheet partly folded; F i 5 is a plan view of the completed sleeve blari k after the first fold; Figs. 6 and 7 are sections on the lines 66 and 77, respectively, of Fig. 5 and on the left and right hand ends, respectively, on the line 67 on Fig. 8; Fig. 8 is an end view of the sleeve blank with the second fold completed, looking from the unkm away; Fig. 10 is a view on the line 1010 trated quite fully, and some alternative feaderend of the blank, as viewed in 5;

F1g. 9 is a view of the corner of a valve bag with the valve sleeve therein, the bag being in section and a part of the sleeve being bro- 55 of Fig. 9; Fig. 11 is a sectional view of a bag with the sleeve therein and with a filling tube inserted in the sleeve; Fig. 12 is a section on the line 12-12 of Fig. 11; Fig. 13 is a view similar to Fig. 11, but showing the ba being removed from the fillingtube, after ling; Fig. 14 is a view on the line 14'14 on Fig. 13; Fig. 15 is a sectional view of the valve corner of the bag and the sleeve therein after the bag has been filled and tipped over on its side, with the valve up; Fig. 16 is a view on the line 1616 of Fig. 15; Fig. 17 is a lan view of the corner of the bag shown in ig. 15; Fig. 18 is a section on the line 1818 of Fig. 15; Fig. 19 is a section through the valve corner of the bag after the bag has been turned over so that the valve end is downward; Fig. 20 is a section on the line 2020 of Fig. 19; Fig. 21 is a view similar to F 9, but showing a modification of the sleeve; Figs. 22, 23 and 24 are diagrammatic views showing successive positions of the interlocking flaps of the valve; Fig. 25 is a view similar to Fig. 5 showing elastic means for assuring the interlocking of the flaps; Fig. 26 is a view similar to Fig. 5 showing spring means for insuring interlocking of the flaps; Fig. 27 is a section of the form of sleeve shown in Fig. 26 when closing; Fig. 28 is a similar view showing the position of the parts when the valve starts to open; and Fig. 29 is a perspective view of one of the spr1n s employed in the form of sleeve shown in i 26.

In the construction shown in igs. 1 to 20, there is a sleeve positioned in the inlet opening of the bag. This sleeve is formed from a sheet of paper shown in plan view in Fig. 1. Fold lines are indicated by dotted lines on that figure. The sheet is folded first along cross line 30 and then along the median longitudinal line 31 to form a sleeve. Adjacent the edges of the sheet are longitudinal fold lines 32 and 33. The ortions 34 and 35 outside of these lines orm edges which are placed in the seam of the bag and sewed together to complete the sleeve and hold it in position in the bag. A bag 36, suitable for use with this sleeve, is indicated in Fig. 9, the bag having a gusset fold 37 and having one corner 38 folded in to form a valve flap. After the sleeve-forming sheet hasbeen placed in the corner of the bag, it is secured in place by seam 39 which closes the end of the bag.

Midway between fold lines 31 and 32, there is a fold line 40, and midway between 31 and 33 there is a fold line 41. The triangular piece shown in Fig. 2 is placed on the sheet so that it extends symmetrically from opposite sides of line 40 and the blank shown in Fig. 3 is placed upon the sheet so that it extends symmetrically from opposite sides of line 41. The smaller end 42 of the blank shown in Fig. 2is provided with a slit 43 which is placed over line 40. Edge portions 44 and 45 extending from the end 42 are pasted to the sheet. About midway on each side of the blank the sides are sllt at 46 and 47 and the edges 48 and 49 of the blank from these slits to the wider end of the blank are folded under about lines 50 and 51 and pasted to the sheet. In pasting the blank to the sheet, the portions 48 and 49 are moved slightly together so as to reduce the angle between ines 50 and 51 and make the material between these lines somewhat full. A central portion is cut awa at 52, and across the wider end of the blan there is left a strip 53. Part of the. fullness of this strip 53 is taken up by a small fold 54 immediately 36 above line 40, and this fold or pleat may be held in sitlon by staples 55, as shown in Fig. 4. etween cut out portion 52 and slit 43 there is formed a small pleat 56 directed upward on the sheet. The cut-out portion 0 52 is preferably excised in such a manner as to leave projections 57 near the middle portion of the blank. Notches 58 and 59 are formed in the outer edges of strip 53.

The upper end of the sheet as viewed in as Fig. 1 is out along a slanting line 60 between line 40, line 32 and along slanting line 61 between line and line 31. Fold lines 62 and 63 extend outward and upward from line 40 to lines 32 and 31, res ctively. Lines 64 and 65 slant downward rom the points where lines 62 and 63 reach lines 32 and 31 to a point on line 40 above where it is reached by lines 62 and 63. From the same points on lines 32 and 31, fold lines 66 and 67 slant downward slightly to line 40, but lines 66 and 67 are at only a slight angle. It will be seen that when the paper is folded along these lines, as shown in Fig. 4, there is formed a point 68 projecting outward where lines 64 and meet line 40, and a oint 69 projecting inward where lines 66 an 67 meet line 40.

The narrow upper end 70 of the blank shown in Fig. 3 is provided with a slit 71 which placed over line 41. The edges 72 I and 73 of the blank, to about lines 74 and 75,

are pasted to the sheet, being swung together meet line 31, the sheet is cut on an outwardly slanting line approximately to line 41. A similar line 81 slants symmetrically down on the other side of line 41 to line 33. Fold lines 82 and 83 slant upward and outward from line 41 to meet lines 80 and 81 at lines 31 and 33, respectively. Fold lines 84 and 85 slant downward and inward from the outer ends of lines 80 and 81 to line 41, these lines slanting downward somewhat more than lines 66 and 67, but not as much as lines 64 and 65. The sheet along line 41, from its upper-end to where it is joined by lines 84 and 85, is provided with a slit 86. The material above line 84 forming flap 87 and the material above line 85 forming flap 88 is bent downward and pasted in the downwardly folded position shown in Fig. 4.

When the upper portion of the sheet is folded downward about line 30 upon the lower portion of the sheet, as shown in Fig. 5, it will be readily seen that the outward projecting portion 56 lying under the portion of line 40 between lines 62 and 63, raises point 68 while point 69 rests opening 52 and flap 89, constituting the portion of the sheet originally above lines 66 and 67, is raised by pleat 54. Similarly, flap 90 between lines 82 and 83 is raised by pleat 79.

It will be understood that not only is the blank shown in Fig. 1 preferably creased along the various fold lines indicated before being assembled, but the blanks shown in Figs. 2 and 3 are also folded along lines 50, 51, 74 and 75 and also long central longitudinal lines which overlie lines 40 and 41 in assembled position.

When the two sides 34 and 35 are folded upward about line 31, point 68 comes in contact with flap 90 while flap 89 enters notch 76 just inside of'ears 77 and 78, which ears rest against strip 53 approximately in registry with notches 58 and 59.

It will be readily understood that the sleeve-forming sheet, folded in this manner, is placed in the corner of the bag 36 and secured in place by a seam 39. In this condition the sleeve is collapsed as indicated in Fig. 10, and the bag is bundled and shipped to its place of use with the sleeve in this position.

The bag is filled by thrusting a filling tube 91 through the filling opening through the sleeve, and material is discharged into the pasted along lines 40 and 41, they tend to bag to fill the same. Flaps 89 and 90 are held apart by the filling tube, as shown in Fig. 12.

After the bag has been filled, its upper end is moved away from the fillin tube, as indicated in Fig. 13. When this is done, there is some tendency for the inner end of the sleeve to return towards its initial position so that the vertical section of the sleeve is greater at its inner end than at its outer end, as indicated in Fig. 13, and the horizontal cross section is somewhat reduced at its inner end, as indicated in Fig. 14. This action of the sleeve is not necessary, but is advantageous, as it favors the folding of the blanks and inner portion of the sleeve along the predetermined fold lines.

It will be readily seen that as the sleeve moves from the position in which it is shown .in Fig. 10 with fold lines 40 and 41 brought together towards the position in which it is shown in Fig. 19, with fold lines 40 and 41 spread fully apart it will move through the position in which it is shown in Figs. 15 to 18, in which the outer portion of the sleeve is I substantially diamond-shape.

As the outer portion moves from a position in which it is collapsed along one diameter through the diamond-shape to a position in which it is collapsed along a diameter at right angles to the first diameter, the inner portion of the sleeve is folded upon itself in the following manner.

When the portions of the blanks pastedto' the sheet are brought towards each other by move inward instead of outward, because of the fullness along pleats 54, 56 and 79. As pleat 56 moves inward, it starts point 68 inward ahead of it. After this movement of oint 68 hasbeen begun, it will be readily understood that it is continued by the bringing together oflines 62 and 63'. It willbe a readily seen that when the sheet is folded to the position in which it is shown in Fig. 19, lines 32 and 33 are brought into position adjacent to line 31. This swings the ends of lines 62 and 63 together, which by toggle action moves point 68 in one direction, 69 in the other direction and flap 89 in the same direction as point 68. Flap 89 is started in the desired direction by pleat 54.

At the same time, flap 90 is started inward by pleat 79 and continues to move inward both because of the pressure of pleat 79 created when lines 31 and 33 are brought together, and also by the toggle action of the flap between line 41 and lines 82 and 83. The stifi'ened portions of flap 90 created by the pasting of flaps 87 and 88 backward upon the body of the sheet assist in assuring the movement of this flap in accordance with and line .31 is brought u next to 84 and is between the angles of lines 66 and 67 on one side and lines 64 and 65 on the other, the point of flap will move inward at a point inside of point 68 and outside of point 69, while flap 89 moves inward past the end of flap 90.

Figs. 22, 23 and 24 show successive ositions of the interlocking fla s 89 and 90, other ortions of the sleeve an bag being move for purposes of illustration. It will be apparent from these views that when the lines 40 and 41 of the sleeve are sp me 33, the end of flap 90 olds into the pocket formed by folds of paper about point 69, so that flap 90 lies between point 68 and'flap 89. Any material, moving outward into the sleeve presses flap 89 against flap 90 and thus a non-leaking closure for the valve is effected; j

By the same movement which interfolds flaps 89 and'90,strip 53 is moved inward beyond the end of flap 89, and ears 77 and 78 slip into notches 59 and 58 respectively and tend to hold the'valve in its closed position so read apart s 32 and moved into the position in which it is shown in Fig. 19, the pressure is relieved so that the yalve returns towards the position in which it 18 shown in Figs. 15 to 18, these ears aid in holding the respective flaps in their overlapping position and prevent any re-opening of the valve to permit seeping of material outward therethrough'.

The construction shown in Fig. 21 is much like that shown in Fig. 9, and similar reference characters, with the addition of the exponent a, are used for similar parts. In the structureshown in Fig. 1 the edge of the sleeve-forming sheet is extended and is folded back along line. to form a flange 101 which stifiens the edge of the sleeve and may ing of the flaps. Parts similar to those in Figs. 1 to 20 are designated by the same reference numbers with the addition of the exponent b. An elastic string 102 runs'along the edge-of flap 90". A similar string 103 runs along the fold lines adjacent flap 89 and a string 104 runs from the edge of flap 89 through point 69 to point 68". These strings are so arranged as to start the folding of the flaps along desired lines to interfold as indicated in Figs. 22 to 24.

The sleeve shown in Figs. 26 to 29 is sim- 90: that evenif, after the valve hasonce' been ilar to that shown in Fig. 25 except that springs are relied upon to initiate the proper folds. Parts similar to those shown in Figs.

1 to 20 are designated by the same reference 5 number with the addition of 0. An L- shaped spring 105-is secured with its long member 106 along line 41 between the layers of the folded sleeve and tending to spring inward as shown in Figs. 27 and 28. Preferably the parts are so proportioned that flap 89 clears the end of spring 106 in closing, as shown in Fig. 27, but encounters the end of the spring, as shown in Fig. 28, when there is movement of the parts in valve-opening direction. This aids in preventing accidental re-opening of the valve after it has been closed.

A spring 107 may be secured between the folds of the sheet, and may be provided with a normally upturned end 108 tending to press point 68 towards the position in which it is shown in Figs. 27 and 28, and a normally upturned end 109 tending to start flap 89 away from the'sleeve-forining sheet and towards the middle of the filling opening.

. The sleeve is preferably of sufficiently stifl material so that it will bend along fold lines. Since it has a fold line opposite the seam of the bag it readily folds along that line to lie flat in the plane of the bag during transportation or storage of the bag. Since it has other fold lines half-way between the first mentioned fold'line and the seam, it opens out in substantially diamond shape during a the filling operation and when the bag has been filled and is inverted-to place the weight of the material upon the valve, the sleeve readily flattens, bringing the first mentioned fold line adjacent the seam of the bag. Even when no flaps are provided within the sleeve, the use of such a sleeve having predetermined fold lines tends to cause the valve to collapse in a regular-predetermined manner so that the edges lie flatly against each other and the valve closes more securely than it would if merely crumpled up instead of being flattened out along predetermined fold lines.

While any considerable variation in the relative lengths or arrangements of the fold lines disclosed in the drawings will interfere with the proper interfolding of the flaps, it will be apparent that flaps might be made to interfold in other ways and along other I lines; and while it is considered preferable to form the interfolding fla s on aseparate sheet which can be inserte into the valve opening, it would be possible to arrange intel-folding flaps on the inturned wall of the bag. A material is desirable which is somewhat flexible, in which definite fold lines can be formed, and which is stiff enough so that it will re-fold along fold lines more readily than along, new lines. Paper meets these conditions, and is readily available.

05 The flaps have a tendency to fold along the predetermined fold lines, but unless provision is made for starting the flaps inward they may remain against the outer sheet of the sleeve. Different devices have been shown for initiating the inward movement of the flaps. After they are once started in the right direction, the stiffness of the material continues to force them in the desired direction. Other means might be utilized for initiating the proper movement of the flaps, including the natural resiliency of the material along the fold lines. Other variations ma be made within the scope of the appende claims.

What is claimed is:

1. A bag having an end-closing seam and a filling opening at one end of the scam, the walls around said opening being of a character to receive definite fold lines and having formed therein a fold line on the side of the opening opposite the seam and a fold line on each side midway between the seam and the first said fold line, all of said fold lines being substantially parallel with said'seam.

2. A bag having an end-closing seam and an opening at one end of the seam and a sleeve in said filling opening, said sleeve being of material in which definite fold lines can be formed and having a fold line in its side opposite the seam and parallel therewith and afold line on each side substantially half p ay between the seam and the first said fold 3. A bag having a filling opening therein and inwardly turned flaps at the sides of said opening, said flaps being provided with fold lines about which they bend more easily than at other points, said fold lines being'arranged to facilitate the folding of the flaps in overlapping relation across the filling opening.

4. A bag having a filling opening therein and inwardly turned flaps at the sides of said opening, said flaps bemg mounted on the walls surrounding the opening along fold lines slanting apart inwardly, whereby the flaps are folded across the opening when the walls thereabout are collapsed by material within the bag.

5. A bag having a filling opening and an inturned wall at one side of said opening said.

wall being provided with a pocket fla the opening of the pocket being towards t e interior of the bag. I Y

6. A bag having a filling opening and an inturned wall at one side of said opening, and a 'V-shaped flap secured along its sides to the wall and having its apex pointing outward.

7. A bag having a filllng opening and an inturned wall at one side of said 0 ning, a V-shaped flap secured along its si es to the wall and having its apex pointing outward, and there being fold lines along the sides of said V and along its median line.

8. A bag having a filling opening and an inturned wall at one side of said opening, a

V-shaped flap secured along its sides to the wall and having its apex pointing outward, and there being fold lines along the sides of said V andalong its median line, and means tending to start said median line away from said wall. 9. A bag having a filling openin and inturned walls on opposite sides of sai opening and pockets on the sides of said walls towards each other, the pockets opening towards the interior of the bag.

10. A bag having a filling opening and inturned walls on the opposite sides of said filling opening and a V-shaped pocket formed in each wall, the pockets opening towards the interior of the bag and havmg fold lines along their edges and along their median lines.

11. A bag having a filling opening and inturned walls on the opposite sides of said filling opening, a V-shaped pocket formed in each wall, the pockets opening towards the interior of the bag and having fold lines along their edges and along their median lines, and means tending to start said median lines away from the adjacent walls.

12. A bag having a filling opening and:

inturned walls on the opposite sides of said filling opening and a V-shaped pocket formed in each wall, the pockets opening towards the interior of the bag and having fold linesalong their edges and along their median lines and overlapping across said opening when collapsed along said fold lines.

13. A bag having a filling opening and inturned walls on the opposite sides of said filling opening, a V-shaped pocket formed in each wall, the pockets opening towards the interior of the bag and having fold lines 40 along their edges and along their median lines and overlapping across said openin when collapsed along said fold lines, an means tending to maintain said overlapping relation after it has been assumed.

14. A bag having a filling opening, a sleeve in said opening composed of a plurality of layers, the inner layer having fold lines running towards each other from its inner edge and outlining a V and a fold line medially along each V.

15. A bag having a filling opening, a sleeve in said opening composed of a plurality of layers, the inner layer having fold lines runningtowards each other from its inner edge and outlining a V, a fold line medially along each V, and means between the layers of the sleeve tending to start said median lines towards each other.

16. A bag having a filling opening, a

.9 sleeve in said opening composed of a plurality of layers, the inner layer having fold lines running towards each other from its inner edge and outlining Vs, and a fold line medially along each V, the edge between the sides of one V being notched in shallow V- form and between the sides of the other V' extending toward the interior of the bag, the material of the last said V having therein two V-shaped fold lines, one deeper and the other shallower than said notch.

17. A bag having a filling opening, a sleeve in said opening composed of a lurality of layers, the inner layer having old lines running towards each other from its inner edge and outlining Vs, a fold line medially along each V, the edge between the sides of one 'V being notched in shallow V-form and between the sidesoof the other V extending toward the interior of the bag, the material of the last said V having therein two V-shaped fold lines, one deeper and the other shallower than said notch, and means between the layers tending to start said median lines towards each other and rovided with means tending to maintain t e edges of said We in overlapped relation after they assume that relation.

18. A bag having an end-closing seam and a filling opening at one end of the seam, the walls around said opening being of a character to receive definite fold lines and having formed therein a fold line on the side of the. opening opposite the seam and a fold line on each side midway between the seam and the first said fold line, all of said fold lines being substantially parallel with said seam, and a V-shaped flap arran ed symmetrically on each of said midway old l nes and with its apex directed outward, there being a median fold line along each flap.

19. A bag having an end-closing seam and a filling opening at one end of the seam, the walls around said opening being of a character to receive definite fold lines and having formed therein a fold line on the side of the opening opposite the seam and a fold line on each side midway between the seam and the first said fold line, all of said fold lines being substantialy parallel with said seam, and a V-shaped flap arranged symmetrically on each of said midway old lines and with its apex directed outward, there being a median fold line along each flap, said flaps overlapping across said opening when the opening-wall opposite the seam is pressed towards the seam.

20. A bag having an end-closing seam and an opening at one end of the seam and a sleeve in said filling opening, said sleeve being of material in which definite fold lines can be formed and having a fold line in its side opposite the seam and parallel therewith and a fold line on each side substantially half way between the seam and the first said fold line, said sleeve being composed of a plurality of layers, the inner layer having fold lines running towards each other from its inner edge and outlining Vs, a fold line medially along each V, the edge between the sides of one V being notched in shallow V.-form and between the sides of the other V extendin toward the interior of the bag, the materia of the last said V having therein two V-shaped fold lines, one deeper and the other shallower than said notch, and means between-the layers tending to start said median lines towards each other and provided with means tending to maintain the ed of said Vs in overlapped relation after e y assume that relation.

In testimony whereof I have hereunto signed my name to this specification.

MARVIN R. KENDALL. 

